In evolutionary cell biology, mitochondria and chloroplasts are classified as semi-autonomous organelles that originated through endosymbiotic events. Which of the following statements correctly describe the structural and genetic characteristics supporting their endosymbiotic evolutionary origin? (Select all correct options)
- Both organelles contain their own circular, double-stranded DNA molecules that are naked and devoid of extensive histone protein complexes, resembling bacterial genomes.Answer
- Both organelles contain 70S ribosomes within their internal compartments that are sensitive to antibacterial antibiotics such as chloramphenicol.Answer
- CBoth organelles are fully autonomous and synthesize all their required enzymes and structural proteins independently of nuclear DNA.
- DBoth organelles divide synchronously with the eukaryotic nucleus during the mitotic M phase through spindle fiber-mediated chromosomal segregation.
Answer
The statements highlighting circular histone-free DNA genomes and bacterial-type 70S ribosomes sensitive to antibiotics are correct.
The correct statements correctly identify the core molecular evidence supporting the Endosymbiotic Theory: mitochondria and chloroplasts maintain circular, histone-free DNA genomes analogous to prokaryotes, and possess 70S ribosomes whose protein synthesis is susceptible to bacterial antibiotic inhibitors.
Step-by-Step Solution
Key Concept
Endosymbiotic Theory and Characteristics of Semi-Autonomous Organelles
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